This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a continuation of a phase 2 study that was done at this center (LA Biomed project # 13028). The purpose of this study is to determine how two new oral formulations (medications to be taken by mouth) of male hormone Testosterone (also called T-esters) are metabolized (broken down) by human body. This will be done by giving different doses of T-esters to hypogonadal men (men deficient in male hormone) and measuring how much of these medications remain in the blood at set time points. These new formulations contain male hormone testosterone in the form of Testosterone Enanthate (TE) or Testosterone Undecanoate (TU) combined with a lipid (fatty) compound. TE has been used as an injection for the treatment of hypogonadal men for over 50 years and is the standard of care in the United States, but there is no oral preparation of TE currently available. Oral TU and recently TU injections are approved in Europe, Aisa, and Australia for male hormone replacement therapy in hypogonadal men. Currently, there are no oral testosterone esters available for hypogonadal men in the United States. It is believed that the new formulations that are being used in this study will be superior to the currently available therapies in several ways. The TU preparation under study is formulated differently from the TU marketed in other countries and it is anticipated that this new TU preparation may produce blood testosterone levels that last longer.